Liquid crystal displays have expanded their practical applications ranging from displays for pocket- or desktop-calculators to those for word processors and personal computers, due to their remarkably improved displaying performance. Furthermore, the liquid crystal displays have been widening their markets wherein the displays are used for personal digital assistants (PDA) because the displays can make the best use of their peculiar characteristics, i.e., thin in size and light in weight. The personal digital assistants are strongly demanded to be decreased in thickness and weight, and particularly required to decrease the thickness and weight of the displays. In response to such strong demands from the users, the decrease of thickness of a polarizer has been in progress by thinning the starting substance thereof, i.e., a resinous substrate film. However, it was difficult to decrease the thickness of an optical retardation plate constituting a polarizer due to the characteristics of the optical retardation plastic film.
In an optical retardation plate wherein a liquid crystal film is used, only the liquid crystal film exhibiting an optical retardation function is a thin film, but it was difficult to decrease the total thickness of the retardation plate due to the presence of a supporting substrate film which also has a function of protecting the liquid crystal layer.
As a technique capable of solving these problems, Japanese Patent Laid-Open Publication No. 8-278491 discloses a method of producing an optical element using a liquid crystal film which is free of a supporting substrate film.
However, although this method has an advantage that a remarkably thin optical element can be obtained because of the use of a liquid crystal film from which a supporting substrate film taking up a major portion of the film thickness is excluded, but also has a disadvantage due to the absence of a supporting substrate film, i.e., a problem that a warp or distortion assumedly caused by various stress generated during the manufacturing and processing processes adversely affects directly the liquid crystal film layer in which, therefore, fine wrinkly deformations and cracks would be formed.
There is a method proposed as one of the means for solving the problem in which method a post-treatment such as heat-aging is conducted for removing warps and distortions. However, this method may not always solve the problem completely and creates another problem of an additional tedious post-treatment.
The object of the present invention is to provide an elliptical polarizer comprising as a constituting element a thinned optical anisotropic element which does not pose problems of the occurrence of fine wrinkly deformation of and cracking in the liquid crystalline substance layer assumedly caused by various stresses generating during a manufacturing/processing steps without employing an additional tedious post-treatment such as heat aging, and a liquid crystal display device equipped with such an elliptical polarizer.